Vacuum cleaner

ABSTRACT

A vacuum cleaner including a surface cleaning head defining an inlet. A container for collecting dirt and dust and a primary passageway connecting the inlet in the cleaning head to the container. Suction means for drawing dirt and dust in through the inlet in the cleaning head along the primary passageway and into the container. One or more secondary inlets are provided on a surface of the vacuum cleaner remote from the inlet in the cleaning head, in order to drawn in airborne dirt and dust.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a Continuation of International ApplicationNo. PCT/GB01/01481, filed Apr. 4, 2001, which was published in theEnglish language on Oct. 18, 2001, under International Publication No.WO 01/76444 A1 and the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to electric appliances, namelyvacuum cleaners.

[0003] Vacuum cleaners work by suction. An electric motor in the cleanerdrives a fan that pumps air from a chamber within the cleaner to createa vacuum. This vacuum is employed to draw air laden with dust and dirtfrom a surface into a dust bag or into a collection compartment withinthe cleaner which retains the dirt and dust. The air is expelled throughan outlet in the body of the cleaner.

[0004] Typically, there are two types of vacuum cleaners, the cylindervacuum cleaner and the upright vacuum cleaner. In the cylinder vacuumcleaner, a flexible hose connected to a cleaning attachment is providedand the cleaning attachment is passed over a surface to be cleaned todraw air laden with dirt and dust into the collection compartment ordust bag via the hose. In the upright vacuum cleaner, air is drawn intothe collection compartment or dust bag through an inlet in a base orfoot unit which comprises wheels to allow the cleaner to be pushed andpulled over the surface to be cleaned. To further improve the cleaningaction of the cleaner, a rotating brush is provided across the inlet inthe base unit that beats dirt and dust out of the surface to be cleaned.Some upright cleaners are also provided with a flexible hose andcleaning attachment like the cylinder type for the purpose of cleaningsurfaces such as floors and upholstery, and means for switching suctionbetween this and the base unit of the cleaner.

[0005] Conventional vacuum cleaners of both types are effective indrawing in dirt and dust from the surfaces on which the cleaningattachment or base unit is used. However, they do not draw in airborneparticles of dirt and dust. Indeed, the very act of vacuuming can causelarge quantities of dirt and dust to become airborne, thereby avoidingthe cleaning action of the vacuum cleaner. In this regard, air expelledfrom the vacuum cleaner blows dirt and dust into the air, movement ofthe cleaning attachment or base causes dirt and dust to become airborneand even the movement of the operative can raise dirt and dust into theair. The presence of these airborne particles of dirt and dust can be aproblem for those people who have dust allergies.

BRIEF SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to provide a vacuumcleaner which draws airborne particles of dirt and dust into thecleaner.

[0007] According to the present invention there is provided a vacuumcleaner comprising: a body which houses a container in which iscollected dirt and dust. A surface cleaning head defines a primary dirtand dust collection inlet able to contact, in use, a surface over whichthe surface cleaning head is moved. A passageway connects the primaryinlet to the container. A secondary dirt and dust collection inlet isremote from the primary inlet and spaced, in use, from the surface.Suction means draw dirt and dust through the primary and secondaryinlets into the cleaner. The primary inlet is adapted to drawsurface-borne dirt and dust efficiently into the cleaner and thesecondary inlet is adapted to draw airborne dirt and dust efficientlyinto the cleaner.

[0008] Airborne particles of dirt and dust from around the cleaner maybe sucked into the cleaner by the secondary inlet(s). The advantage ofthis is that dirt and dust are removed from the room environment and notjust from the surface.

[0009] There may be only one secondary inlet, in which case it ispreferably in the form of a slot. Preferably, however, there is an arrayof secondary inlets.

[0010] The relative cross sections of the first and second inlet can beused to balance the performance of each inlet. Preferably, the crosssection of the second inlet is less than two hundred percent (200%) ofthe cross section of the first inlet, ideally less than one hundredpercent (100%). Preferably, the cross section of the second inlet isgreater than five percent (5%) of the first inlet, preferably greaterthan ten percent (10%).

[0011] In a preferred embodiment adjustable dampening means may beprovided to the first inlet, the second inlet or both first and secondinlets so as to adjust the performance of each inlet. Operatoradjustments to performance can then be made to adjust the vacuum cleanerto differing cleaning environments, for example, carpet type, room size,levels of dust etc. In a further embodiment, the dampening means may becontrolled by an actuator, which may be activated directly or indirectlyby the operator to pre-set positions. Electronic control means may beused within the vacuum to control the actuator(s). Sensors may bepresent in the vacuum cleaner to feed information into the electroniccontrol means which may automatically adjust the dampening means via theactuator(s) during operation in response to the sensor information.Sensors may detect air flow, pressure or levels of dirt.

[0012] The dampening means may be any suitable feature known to open orclose air inlets, for example, a slideably mounted inlet shutter, airvalve, constricting/dilating passageway or a switch to the suction meansor any combination thereof.

[0013] The electronic control means includes any conventional solidstate system or circuit board able to process information input from anyoptionally present sensor or from the operator and effect a changedirectly to the dampening means or indirectly to the dampening means viathe actuator(s).

[0014] In an alternative embodiment, the dampening means are provided tothe first and second inlet and are independently able to fully open andfully close, or any position in between, each inlet. Such an orientationof the device allows the vacuum cleaner to be switched between solelytaking in air from the primary inlet or the secondary inlet or in anyproportion in between.

[0015] The secondary inlet(s) may be connected into the passagewayconnecting the surface cleaning head to the dust and dirt collectioncompartment in which case both the surface cleaning head and thesecondary inlet(s) may share a common suction means. Alternatively, aseparate passageway, or passageways, may be provided to connect thesecondary inlet(s) to the dust and dirt collection compartment. In thislatter case, it may be convenient to provide separate suction means foreach passageway.

[0016] Suction means will invariably involve an electric motor and/or afan. These components are conventional in the field to draw the airthrough the cleaner. The suction means may draw the air through bothinlets by way of a single motor drawing air through both inlets or twomotors one for each inlet. A single motor could simultaneously draw airthrough both inlets by driving a fan in each inlet.

[0017] In a preferred orientation of the single motor in which thesecond inlet is connected to the passageway of the first inlet, thecross-sectional area of the secondary inlet relative to thecross-section of the primary inlet will primarily determine the relativeair flows between the two inlets.

[0018] Dust filtering means, such as an electrostatic filter, may beprovided between the secondary inlet(s) and the compartment. This may beappropriate when the air drawn into the secondary inlet(s) (“secondaryair”) is conveyed over the suction means or part of it (that is, over afan and/or motor). This may be done to effect cooling. Preferably,however, secondary air is not thus conveyed. Preferably, also, no suchdust filtering means between the secondary inlet(s) and the compartmentis provided.

[0019] With upright vacuum cleaners typically having a wheeled base unitwhich contains the primary inlet, and articulated to an upright mainbody which contains the dirt and dust container, there is preferably aplurality of secondary inlets provided in an upper surface of the baseunit or in the main body thereof, or in both. With cylinder vacuumcleaners, typically having a single, generally drum shaped, a wheeledbody and carrying a cleaning head comprising the primary inlet on aflexible tube, there is preferably a plurality of secondary inletsprovided in the body thereof, preferably in the upper region thereof.Alternatively or additionally one or more tubes may extend over theouter casing of the vacuum cleaner, whether of upright or cylinder type,and include a plurality of secondary inlets therein at intervals alongits length through which airborne particles of dirt and dust can bedrawn. In one such embodiment of the present invention, such a tubeextends in a helix around the main body or on the upper surface of thevacuum cleaner.

[0020] Preferably the secondary inlets of an array are reasonably wellspaced from each other.

[0021] Preferably, the secondary inlets of an array are notunidirectional. Unidirectional, in this situation, means all facing inthe same direction.

[0022] Preferably, at least one secondary inlet of an array facesgenerally forwards.

[0023] Preferably, at least one secondary inlet of an array facesgenerally rearwards.

[0024] Preferably, at least one secondary inlet of an array facesgenerally sideways.

[0025] Preferably, at least one secondary inlet of an array facesgenerally sideways in one direction and at least one secondary inlet ofan array faces generally sideways in the opposite direction.

[0026] If wished, at least one secondary inlet of an array facesgenerally upwards.

[0027] Suitably there are at least three (3) secondary inlets in anarray, preferably at least five (5), more preferably at least eight (8),and most preferably at least ten (10).

[0028] Alternatively or additionally, a secondary inlet may be in theform of a single slot that is not unidirectional. Unidirectional, inthis situation, refers to a straight slot provided in a planar face.

[0029] Preferably, a secondary inlet in the form of a single slot has aportion which faces generally forwards.

[0030] Preferably, a secondary inlet in the form of a single slot has aportion which faces generally rearwards.

[0031] Preferably, a secondary inlet in the form of a single slot has aportion which faces generally sideways.

[0032] Preferably, a secondary inlet in the form of a slot has a portionwhich faces generally sideways in one direction and a portion whichfaces generally sideways in the opposite direction.

[0033] A secondary inlet in the form of a slot may extend substantiallyall the way around the cleaner, such that it can draw in airborne dirtand dust from the front, rear and both sideways directions. Thus, itcould be an endless slot or a generally helical slot.

[0034] If desired, a secondary inlet in the form of a single slot has aportion which faces generally upwards.

[0035] The words “forwards”, “rearwards”, “sideways” and “upwards” areused herein with reference to the vacuum cleaner in its normalconfiguration and orientation in use, with the cleaning head at thefront but are not meant to be limiting.

[0036] In accordance with a second aspect of the present invention thereis provided a method of cleaning using a vacuum cleaner of the inventionas defined herein, whereby dust and dirt are drawn in from a surfacethrough the primary inlet and from the air by the secondary inlet.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0037] The foregoing summary, as well as the following detaileddescription of preferred embodiments of the invention, will be betterunderstood when read in conjunction with the appended drawings. For thepurpose of illustrating the invention, there is shown in the drawingsembodiments which are presently preferred. It should be understood,however, that the invention is not limited to the precise arrangementsand instrumentalities shown.

[0038] In the drawings:

[0039]FIG. 1 shows a partial sectional view of a conventional uprightvacuum cleaner; and

[0040]FIG. 2 shows an upright vacuum cleaner according to a firstembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0041] Referring to FIG. 1 of the drawings the upright vacuum cleanercomprises a main body 1 (only partially shown), the interior of whichdefines a compartment for the collection of dirt and dust or for housinga dust bag. The body 1 is mounted on an elongate shaft 2, the upper endof which defines a handle (not shown) and the lower end of which ispivotally connected to a base unit 3. The base unit 3 is supported atthe front and rear, on wheels or rollers 4 to facilitate movement of thecleaner over the floor.

[0042] The base unit 3 includes an electric motor 5 that drives a fan 6positioned within a chamber 7. To the rear of the chamber 7 there isprovided a conveying passageway 8, which is connected via a short lengthof flexible hose 9 to the compartment in the main body 1. To the frontof the chamber 7 there is provided in the floor of the base unit 3 anelongate slot 10. The elongate slot 10 extends from one side to theother of the base unit 3. A roller brush 111 is positioned in the slot10 and is supported at each end in the sidewall of the base unit 3. Theroller brush 11 is rotatably driven by the electric motor 5 actingthrough an extension to the drive shaft 12 which supports the fan 6 anda drive belt 13.

[0043] As was described hereinabove, the upright vacuum cleaner isconventional. Dirt and dust are beaten out of the surface on which thecleaner is supported by the action of the rotating roller brush 11. Thedirt and dust is then drawn into the chamber 7 as a result of the vacuumcreated by the fan 6. The increased air pressure behind the fan 6 pushesair laden with dirt and dust along the conveying passageway 8, throughthe flexible hose 9, and into the compartment in the main body 1.

[0044] The base unit 3 is also provided with an array of secondary airinlets 20 in the upper face thereof. The inlets 20 are spaced from eachother in a circular array, of which two can be seen in FIG. 1 (onefacing generally forwards and the other facing generally rearwards, andwith others, not shown, facing in other directions around the circle). Afurther secondary inlet is at the center of the circle, shown as 21,facing generally upwards. It will be appreciated that air from aroundthe cleaner is drawn in through the secondary inlets 20, 21 carryingwith it airborne particles of dirt and dust. This air joins with themain column of air drawn in through the passageway 8 and the hose 9 andis drawn into the compartment in the main body 1.

[0045] As is shown in FIG. 1, the secondary air inlets 20, 21 in theupper face of the base unit 3 lead directly into the air intake side ofthe chamber 7 in which the fan 6 is situated. However, it is envisagedthat the secondary air inlets 20, 21 may also be connected into the airoutlet side of the fan 6 at any point prior to the collectioncompartment or dust bag. In this regard, where the velocity of thecolumn of air passing between the fan 6 and the collection compartmentor dust bag is sufficiently high it will entrain air from a spurpathway. This spur pathway is connected to the secondary air inlets 20,21 to allow airborne particles of dirt and dust to be drawn in.

[0046] Referring now to FIG. 2 there is shown another upright vacuumcleaner embodying the present invention. For the purposes of explanationthis can be considered to be identical in all conventional respects tothe one described hereinbefore with reference to FIG. 1. However,instead of having secondary air inlets 20, 21 in the upper part of thebase unit 3, the cleaner is provided with a tube 30 which is wrappedaround the main body 1 thereof. The tube 30 may be a separate componentfrom the main body 1, but preferably is formed integrally with the mainbody 1. The upper end of the tube 30 is closed and the lower end thereofis connected into the base unit 3 to join with the main airwaytherethrough. Small holes 32, several dozen in total, are provided atintervals along the length of the tube 30.

[0047] In use, air around the main body 1 of the cleaner is drawn intothe tube 30 through the holes 32, carrying with it airborne particles ofdirt and dust. From the tube 30 the air passes into the base unit 3where it joins with the main column of air passing therethrough into thecollection compartment within the main body 1.

[0048] The present invention has been described with reference toupright vacuum cleaners. However, it is equally applicable to cylindervacuum cleaners having a wheeled unit containing the container for dirtand dust, and with the cleaning head, having the primary inlet carriedon a flexible tube. Thus, in another embodiment, not shown in thedrawings, a cylinder vacuum cleaner has instead of a multiplicity ofsecondary inlets, a horizontal slot extending all the way around itshousing adjacent to its upper end to serve as the secondary inlet. Theair drawn in through the slot is directed by an internal conduit to thecollection compartment.

[0049] It will be appreciated by those skilled in the art that changescould be made to the embodiments described above without departing fromthe broad inventive concept thereof. It is understood, therefore, thatthis invention is not limited to the particular embodiments disclosed,but it is intended to cover modifications within the spirit and scope ofthe present invention as defined by the appended claims.

We claim:
 1. A vacuum cleaner comprising: a body which houses acontainer in which is collected dirt and dust; a surface cleaning headdefining a primary dirt and dust collection inlet able to contact, asurface over which the surface cleaning head is moved; a passagewayconnecting the primary inlet to the container; a secondary dirt and dustcollection inlet remote from the primary inlet and spaced, from saidsurface; and suction means for drawing dirt and dust through the primaryand secondary inlets into the cleaner, the primary inlet being adaptedto draw surface-borne dirt and dust efficiently into the cleaner and thesecondary inlet being adapted to draw airborne dirt and dust efficientlyinto the cleaner.
 2. The vacuum cleaner according to claim 1, whereinthe secondary inlet is connected into the passageway connecting thesurface cleaning head to the container.
 3. The vacuum cleaner accordingto claim 1, wherein the secondary inlet is connected to the container byway of a separate passageway.
 4. The vacuum cleaner according to claim1, wherein at least secondary inlet is in the form of anon-unidirectional slot.
 5. The vacuum cleaner according to claim 1,wherein the secondary inlet includes an array of secondary inlets. 6.The vacuum cleaner of claim 5, wherein the secondary inlets are notunidirectional.
 7. The vacuum cleaner of claim 6, wherein at least onesecondary inlet faces generally forwards, at least one secondary inletfaces generally rearwards, at least one secondary inlet faces generallysideways in a first direction, and at least one secondary inlet facesgenerally sideways in a second opposite direction.
 8. The vacuum cleanerof claim 1, wherein the vacuum cleaner is an upright vacuum cleanercomprising: a base unit having the surface cleaning head and a main bodywhich houses the container, the secondary inlet is provided in at leastone of an upper surface of the base unit and in the main body.
 9. Thevacuum cleaner according to claim 1, wherein the vacuum cleaner is acylinder vacuum cleaner, the secondary inlet is provided in the upperregion of the main body thereof.
 10. The vacuum cleaner according toclaim 1, wherein dampening means are provided to at least one of theprimary inlet and the secondary inlet.
 11. A method of cleaning with avacuum cleaner including the steps of: a) drawing dust and dirt into aprimary inlet from a surface; and b) drawing dust and dirt into asecondary inlet from atmospheric air of a room.